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A Monte Carlo study of spring-exchange magnets containing ultra-high coercive phases

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Journal of Rare Earths 2019年第10期37卷 1023-1029页

作者： K.Granek G.Zió■kowski A.Chrobak institute of physics University of Silesia

The aim of the present work is to study magnetization processes in the spring-exchange magnetic composites containing magnetically soft, hard and ultra-high coercive phases, experimentally found in Tb-Fe-B-Nb group of alloys. In order to modeling hysteresis loops a special Monte Carlo procedure,suitable for irregular geometry of the composites, was applied. The obtained results indicate that sufficiently strong coupling between soft and hard magnetic phase leads to collective, single-phase-like movement of such phases, which in turn, causes increase of the coercivity and internal magnetic energy.

关键词： Tb-Fe-B Permanent magnet Spring-exchange Monte-Carlo simulations Magnetic composite Rare earths

Riccati-type Bcklund transformations of nonisospectral and generalized variable-coefficient KdV equations

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Chinese physics B 2014年第3期23卷 186-192页

作者：杨云青王云虎李昕程雪苹 School of Mathematics Physics and Information Science Zhejiang Ocean University Shanghai Key Laboratory of Trustworthy Computing East China Normal University School of Mathematics and Statistics Changshu Institute of Technology

We extend the method of constructing Bgcklund transformations for integrable equations through Riccati equations to the nonisospectral and the variable-coefficient equations. By taking nonisospectral and generalized variable-coefficient Korteweg-de Vries （KdV） equations as examples, their Backlund transformations are obtained under a more generalized constrain condition. In addition, the Lax pairs and infinite numbers of conservation laws of these equations are given. Es- pecially, some classical equations such as the cylindrical KdV equation are just the special cases of the constrain condition.

关键词： Baicklund transformation Lax pair conservation law Cole-Hopf transformation

Photodegradable polar-functionalized polyethylenes

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National Science Review 2023年第7期10卷 124-133页

作者： Chaoqun Wang Jian Xia Yuxing Zhang Xiaoqiang Hu Zhongbao Jian State Key Laboratory of Polymer physics and Chemistry Changchun Institute of Applied Chemistry Chinese Academy of Sciences School of Applied Chemistry and Engineering University of Science and Technology of China

The degradation of plastics has attracted much attention from the global ***(PEs),as the most abundant synthetic plastics,are most frequently *** is non-degradable and non-polar because of the sole presence of the pure hydrocarbon *** incorporation of both in-chain cleavable and functional groups into the PE chain is an effective pathway to overcome the non-degradable and non-polar issue;however,the method for achieving this pathway remains ***,we report a strictly non-alternating(>99%) terpolymerization of ethylene with CO and fundamental polar monomers via a coordination-insertion mechanism using late transition metal catalysts,which effectively prevents the formation of undesired chelates originating from both co-monomers under a low CO ***-molecular-weight linear PEs with both in-chain isolated keto(>99%) and main-chain functional groups are *** incorporation of key low-content isolated keto groups makes PEs photodegradable while retaining their desirable bulk material properties,and the introduction of polar functional groups considerably improves their surface properties.

关键词： degradable plastic homogeneous catalysis C1 chemistry non-alternating copolymerization polyolefin

Oxygen Functionalization-Induced Charging Effect on Boron Active Sites for High-Yield Electrocatalytic NH_(3) Production

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Nano-Micro Letters 2022年第12期14卷 464-480页

作者： Ashmita Biswas Samadhan Kapse Ranjit Thapa Ramendra Sundar Dey institute of Nano Science and Technology(INST) Sector-81MohaliPunjab 140306India Department of physics SRM University-APAmaravatiAndhra Pradesh 522240India

Ammonia has been recognized as the future renewable energy fuel because of its wide-ranging applications in H_(2) storage and transportation *** order to avoid the environmentally hazardous Haber-Bosch process,recently,the third-generation ambient ammonia synthesis has drawn phenom-enal attention and thus tremendous efforts are devoted to developing efficient electrocatalysts that would circumvent the bottlenecks of the electrochemical nitrogen reduction reaction(NRR)like competitive hydrogen evolution reac-tion,poor selectivity of N_(2) on catalyst ***,we report the synthesis of an oxygen-functionalized boron carbonitride matrix via a two-step pyrolysis *** conductive BNCO(1000)architecture,the compatibility of B-2p_(z) orbital with the N-2p_(z) orbital and the charging effect over B due to the C and O edge-atoms in a pentagon altogether facilitate N_(2) adsorption on the B edge-active *** optimum electrolyte acidity with 0.1 M HCl and the lowered anion crowding effect aid the protonation steps of NRR via an associative alternating pathway,which gives a sufficiently high yield of ammonia(211.5μg h^(−1) mg_(cat)^(−1))on the optimized BNCO(1000)catalyst with a Faradaic efficiency of 34.7%at−0.1 V vs *** work thus offers a cost-effective electrode material and provides a contemporary idea about reinforcing the charging effect over the secured active sites for NRR by selectively choosing the electrolyte anions and functionalizing the active edges of the BNCO(1000)catalyst.

关键词： C-doped boron nitride O-functionalization Density-functional theory(DFT) Charging effect Nitrogen reduction reaction Ambient ammonia synthesis

Mitigation of the ablative Rayleigh–Taylor instability by nonlocal electron heat transport

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Matter and Radiation at Extremes 2022年第5期7卷 47-54页

作者： Jun Li Rui Yan Bin Zhao Jian Zheng Huasen Zhang Xiyun Lu Department of modern Mechanics University of Science and Technology of ChinaHefei 230026China Collaborative Innovation Center of IFSA(CICIFSA) Shanghai Jiao Tong UniversityShanghai 200240China Department of Mathematics and physics Nanjing Institute of TechnologyNanjingJiangSu 211167China Department of Plasma physics and Fusion Engineering University of Science and Technology of ChinaHefeiAnhui 230026China institute of Applied physics and Computational Mathematics Beijing 10094China

The effects of electron nonlocal heat transport (NLHT) on the two-dimensional single-mode ablative Rayleigh–Taylor instability (ARTI) upto the highly nonlinear phase are reported for the first time through numerical simulations with a multigroup diffusion model. It is found thatas well as its role in the linear stabilization of ARTI growth, NLHT can also mitigate ARTI bubble nonlinear growth after the first saturationto the classical terminal velocity, compared with what is predicted by the local Spitzer–Härm model. The key factor affecting the reductionin the linear growth rate is the enhancement of the ablation velocity Va by preheating. It is found that NLHT mitigates nonlinear bubblegrowth through a mechanism involving reduction of vorticity generation. NLHT enhances ablation near the spike tip and slows down thespike, leading to weaker vortex generation as the pump of bubble reacceleration in the nonlinear stage. NLHT more effectively reduces thenonlinear growth of shorter-wavelength ARTI modes seeded by the laser imprinting phase in direct-drive laser fusion.

关键词： bubble nonlinear stabilization

Thermoelectric coolers:Infinite potentials for finite localized microchip cooling

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Journal of Materials Science & Technology 2022年第26期121卷 256-262页

作者： Zhi-Gang Chen Wei-Di Liu School of Chemistry and physics Queensland University of TechnologyBrisbaneQLD 4001Australia Australian institute of Biotechnology and Nanotechnology the University of QueenslandSt LuciaQLD 4072Australia

With the ever-growing semiconductor and microchip industries,increasing amount and categories of personal electronics have flooded into our daily *** is the key challenge limiting further performance enhancement of the high-speed microchips in *** cooling,a solid-state active cooling method,possesses great potential for localized cooling with the advantages of noise-free,vibration-free,maintenance-free,and liquid-media-free,and can solve the challenge in *** proper material engineering,such as carrier concentration,band engineering,hierarchical architecture engineering,high performance thermoelectric materials with high potential for thermoelectric cooling have been widely *** further proper device design based on state-of-art thermoelectric materials,such as vertical thin film thermoelectric device design,contact interface engineering and thermoelectric and microchip integration,thermoelectric coolers show infinite potentials for finite cooling requirement of microchips.

关键词： Microchip Cooling Thermoelectric Application

Vector meson effects on multi-Skyrmion states from the rational map ansatz

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中国科学:物理学、力学、天文学英文版 2023年第11期66卷 126-135页

作者： Jun-Shuai Wang Yong-Liang Ma College of physics Jilin UniversityChangchun130012China School of Fundamental physics and Mathematical Sciences Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of Sciences(UCAS)Hangzhou310024China TaiJi Laboratory for Gravitational Wave Universe(Beijing/Hangzhou) UCASBeijing100049China

The roles of the lightest vector mesons ρ and ω in the multi-Skyrmion states are studied using the hidden local symmetry approach up to the next-to-leading order,including the homogeneous Wess-Zumino *** low-energy constants in the effective field theory are determined using the Sakai-Sugimoto model and the flat-space five-dimensional Yang-Mills *** only two inputs,m_(ρ) and f_(π),it is possible to determine all low-energy constants without *** vector meson effects can be investigated by sequentially integrating vector mesons,and their geometry can be elucidated by comparing the results using the low-energy constants estimated from the Sakai-Sugimoto model and the flat-space five-dimensional Yang-Mills *** found that theρmeson reduces the masses of the multi-Skyrmion states and increases the overlaps of their constituents,whereas theωmeson repulses the constituents of the multi-Skyrmion states and increases their ***,these vector mesons are crucial in the Skyrme model approach to *** also found that the warping factor,an essential element in the holographic model of QCD,affects the properties of the multi-Skyrmion states and cannot be ignored.

关键词： vector meson multi-Skyrmion state rational map hidden local symmetry

Raman phonon anomalies in Sr(Fe1-xCox)2As2

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Chinese physics B 2022年第2期 648-651页

作者：杨彦兴张鹤巍庄海正 School of physics Communication and Electronics Jiangxi Normal University Department of physics New Jersey institute of Technology

Phonon anomalies have been reported in iron-pnictide superconductors indicating a diverse interplay between different orders in the materials. Here, we report Raman scattering measurements on Sr(FeCox)As(x = 0 and x = 0.04)single crystals in the Bsymmetry with respect to a 1 Fe unit cell. Upon cooling, we observe a larger split(13 cm)of Eg Raman phonon modes pertaining to in-plane Fe and As displacements as the crystals undergo the tetragonal-toorthorhombic structural phase transition, although a considerable split(9 cm) has been reported in Ba(FeCox)***, the splitting of Ephonon modes is strongly reduced upon doping. We perform an order-parameter analysis revealing a similar doping dependence of Ephonon splitting as reported in other compounds of the 122 family, indicating these phonon anomalies widely exist in 122 iron-based superconductors and might share the same mechanisms.

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A high fidelity general purpose 3-D Monte Carlo particle transport program JMCT3.0

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Nuclear Science and Techniques 2022年第8期33卷 175-192页

作者： Li Deng Gang Li Bao-Yin Zhang Rui Li Ling-Yu Zhang Xin Wang Yuan-Gang Fu Dun-Fu Shi Peng Liu Yan Ma Dan-Hu Shangguan Ze-Hua Hu Sheng-Cheng Zhou Jing-Wen Shen institute of Applied physics and Computational Mathematics(IAPCM) Beijing 100094China CAEP Software Centre for High Performance Numerical Simulation(CAEP-SCNS) Beijing 100088China

JMCT is a large-scale,high-fidelity,three-dimensional general neutron–photon–electron–proton transport Monte Carlo software *** was developed based on the combinatorial geometry parallel infrastructure JCOGIN and the adaptive structured mesh infrastructure *** is equipped with CAD modeling and visualizes the image *** supports the geometry of the body and the structured/unstructured *** has most functions,variance reduction techniques,and tallies of the traditional Monte Carlo particle transport *** energy models,multi-group and continuous,are *** recent years,some new functions and algorithms have been developed,such as Doppler broadening on-thefly(OTF),uniform tally density(UTD),consistent adjoint driven importance sampling(CADIS),fast criticality search of boron concentration(FCSBC)domain decomposition(DD),adaptive control rod moving(ACRM),and random geometry(RG)*** JMCT is also coupled with the discrete ordinate SNcode JSNT to generate source-biasing factors and weight-window *** present,the number of geometric bodies,materials,tallies,depletion zones,and parallel processors are sufficiently large to simulate extremely complicated device *** can be used to simulate reactor physics,criticality safety analysis,radiation shielding,detector response,nuclear well logging,and dosimetry calculations *** particular,JMCT can be coupled with depletion and thermal-hydraulics for the simulation of reactor nuclear-hot feedback *** paper describes the progress in advanced modeling,high-performance numerical simulation of particle transport,multiphysics coupled calculations,and large-scale parallel computing.

关键词： Advanced modeling High-performance numerical simulation Multi-physics coupled calculation Large-scale parallel computing JMCT